Common material specifications for bolts and nuts are shown in Table A.
|Material Specifications for Bolts and Nuts and Recommended Bolting Temperature Range|
2. Grade of material, identifying symbol of bolt or nut
● Bolts or stud-bolts
● Nuts, regular or heavy series
● Nominal diameter, length
● Diameter of plain and reduced portion, length of thread (if applicable)
6. Manufacturer’s test certificate (if required). Fully threaded studbolts and heavy series nuts are most common in industrial applications.
High Temperature Bolting Applications
High temperature relaxation is a combined effect of gasket creep, bolt creep, and flange rotation. All three or any combination may occur. The symptoms show up as loose bolts that reduce gasket stress, resulting in increased leakage.